1. Field of the Invention
The present invention relates to a tetrahydrofuran-compound and a novel insecticide containing this compound as an effective component.
The tetrahydrofuran-compound of the present invention is useful as a pesticide (particularly an insecticide) in the agricultural field.
2. Description of the Prior Art
An insecticidal tetrahydrofuran-compound of the present invention can be represented by the formula (1) which will be described hereinafter, but another insecticidal compound having a similar skeleton has been described in Japanese Patent Application Laid-open No. 183271/1986. However, the disclosed compound is a nitromethylene-compound, which is different in structure from the compound of the present invention having a nitroimino group. On the other hand, Japanese Patent Application Laid-open No. 81382/1987 has the description of an insecticide having a skeleton similar to that of the compound of the present invention. In this publication, a compound having a furan ring which is a kind of unsaturated ring as a part of the skeleton is mentioned, but there is not described any compound having a tetrahydrofuran ring which is a kind of saturated ring as a part of the skeleton such as the compound of the present invention. Furthermore, Japanese Patent Application Laid-open No. 156786/1988 has reported a compound having a skeleton similar to that of the compound of the present invention as an intermediate of an insecticide, but in this publication, the insecticidal activity of this intermediate has not been referred to anywhere. Therefore, in the former techniques, there has been found neither the description of compounds having such a structure as in the present invention nor the description of a use as insecticides of these compounds.
Moreover, the above-mentioned patent publications have a description that the compound containing a heterocyclic group in its molecule shows insecticidal activity. However, according to investigations by the present inventors, it has been elucidated that every heterocyclic ring does not show the insecticidal activity. That is to say, among these insecticidal compounds, the compounds having the practical activity as a pesticide are limited to derivatives having a thiazolylmethyl group or a pyridylmethyl group as a part of the skeleton, and this fact has also been reported in an industrial magazine [J. Pesticide Sci., 19, S209 (1994)] and the like. Furthermore, imidacloprid is the only compound which has the pyridylmethyl group as a part of the skeleton, and has now been put to practical use. That is to say, according to the former techniques, although it has been suggested that all compounds containing a heterocyclic group in the molecule shows insecticidal activity, the heterocyclic groups having insecticidal activity are limited. In addition, the practically useful compounds are limited to the derivatives having the pyridylmethyl group as a part of the skeleton.